Lens.



II/I. II. SIIIIITII.

LENS. APPLICATION FILED APR.2,19I1.

Pajblld July 23, 1918. l-W- rn, .assrenon ro non nnss con:

'0F JEANNETTJE, JPENNSYLVhWlh, All. UUPORhllUON 0l? lfESYlhldlllllah.

LENS.

maratea..

hpeclncatilon of Letters Patent.

application mea april. a, reir. serial no.l traina.

To all rwhom t may concern:

lBe it known that l, MAURICE A. SMITH, a citizen of the United States,and resident of Jeannette, in the county of Westmoreland and State ofPennsylvania, have invented a new and useful llmprovement in Lenses; andll do hereby declare the following to be a full, clear, and exactdescription thereof.

My invention relates to lenses for automobile headlights or otherpurposes to which they ma be found applicable.

The o ject of my invention is to -provide a lens of this character inwhich the light Vrays are directed sidewise for lighting the side of theroad, as well as for'turning corners, and providing for the direction oflight rays forwardly and downwardly for a suitable distance and atproper height to prevent dazzling the eyes of pedestrians, the lightrays in no case being directed above the top of the headlight. j

ln the accompanying drawing, Figure l is a face View of my improvedlens; llig. 2 is a section taken on the line 2 2, lig. l, lookingdownwardly; and Fig; 3 is a section on' the line 3 3, lFig. 1.

The numeral 2 designates my improved lens which is made of a glass ofsuitable thickness with the-rim 3 for securing the lens within theheadlight. 'lhe lens is concave on its inner face as at 4l, and convex,as at 5, on its outer face.

'llhe upper portion of the lens for a suiti able distance and preferablyless than half of the area of the lens is provided with the verticaltriangular prisms 6 the outer ones of 4which act to direct the lightrays side.- wise as indicated in lBig. 2, the light on passing throughthe glass being refracted by the prisms according to the welhhoown lawsof light. The inner for central group of thesev vertical prisms givesubstantially total re` llection sothat there is practically no lateraldispersion of light from this central group.

Below the vertical prisms t3 are the horizontal prisms' 7 arranged inthe form of bands with dat faces 8. The lower end of oneprisin or bandprojects out beyond the upperend of the succeeding lower band., and inAthis manner a stepped edect is given as shown in hig. 3. 'lhe faces 8increase in patenten nur a9 rr. A

length as they approach the bottom of the lens. 'lhe ed'ect of thesehorizontally-arranged prisms or bands is to direct the light downwardlyas indicated i'n Fig. 3, but at the same time, projecting the lightsufficient distance to give the lighting .ed'ect for the requireddistance, and at the same time conlining the light rays to a heightwhich will not dazzle or confuse the pedestrian.

lBy my invention, therefore, ll provide a lens which is very simple inconstruction and one in which the light rays are diused sidewise due tothe arrangement of the vertical triangular prisms on its upper portionto give the necessary lighting for the sides of the road, as well as inturning corners, and in which the light rays in the lower portion aredirected downwardly at the proper angle to give sucient distancelighting.

llhat ll claim is:

l.. lln a lens having a concave inner and D convex outer face, a seriesof vertically-disposed triangular prisms at the upper portion of saidouter convex face whereby the light rays are didused laterally by theouter ones of said prisms and the inner or central ones givesubstantially total redaction, and below the same horizontally-arrangedprisms comprising a series of stepped bands with dat faces.

2.. lln a lens having a concave inner and convex outer face, a series ofvertically-dis` posed triangular prisms at the upper portion of saidconvex face for less than onehalf the area of said lens whereby thelight rays are didused laterally by the outer ones of saidvertically-arranged prisms and the inner or central ones givesubstantially total redaction, and below 'the same horizontallyarrangedprisms consisting of bands with Hat faces, the lower end of one bandpro'- jecting out beyond the upper end of the succeedng lower band..

ln testimony whereof, l the said'llllaunron A. SMrrH, have hereunto set)i hand..

MCE STH.

